Criteria

Text:
Topic:
Display:

Results

Viewing 241 to 270 of 15812
Technical Paper
2014-04-01
Venkat Pisipati, Srikanth Krishnaraj, Edgar Quinto Campos
Abstract Motor vehicle safety standards are getting to be more demanding with time. For automotive interiors, instrument panel (IP) head impact protection is a key requirement of the Federal Motor Vehicle Safety Standard (FMVSS) 201. To ensure compliance of this requirement, head impact tests are conducted at 12 and 15 mph for performance verification. Computer simulation has become more prevalent as the primary development tool due to the significant reduction in time and cost that it offers. LS-DYNA is one of the most commonly used non-linear solvers in the automotive industry, particularly for safety related simulations such as the head impact of automotive interiors. LS-DYNA offers a wide variety of material models, and material type 024 (MAT 024, piecewise linear plasticity) is one of the most popular ones [1]. Although it was initially developed for metals, it is commonly used for polymers as well. LS-DYNA also offers several other material models specifically developed to simulate polymers, such as material types 019, 089, 123, to name a few.
Technical Paper
2014-04-01
Sanjeev Kumar, Deepak Katyal, Amit Singh
Abstract Recent advancement in numerical solutions and advanced computational power has given a new dimension to the design and development of new products. The current paper focuses on the details of work done in order to improve the vehicle performance in Offset deformable Barrier (ODB) crash as per ECER-94. A Hybrid approach involving the Structural Crash CAE as well as Multi-body Simulation in MADYMO has been adopted. In first phase of the development, CAE results of Structural deformation as well as Occupant injury of the baseline model were correlated with physical test data. The second phase includes the improvement in intrusion and crash energy absorption by structural countermeasures in the vehicle body. In third phase parametric study has been carried out via Madymo simulation in order to decide on the factors which can be controlled in order to mitigate the Occupant injury. Recommendations of Madymo simulation have been confirmed by conducting Physical sled tests. Finally a cost and weight effective countermeasure package which involves the modification in Body structure and Restraint system has been developed in order to comply with the ECE R-94 offset crash regulation.
Technical Paper
2014-04-01
Alan R. Wedgewood, Patrick Granowicz, Zhenyu Zhang
Abstract Materials used in automotive components play a key role in providing crash safety to passengers and pedestrians. DuPont's lightweight hybrid material technology, which combines injection molded fiber reinforced plastics with drape molded woven composite materials, provides safety engineers with stiff energy absorbing alternatives. In an effort to validate the hybrid material's crash performance while avoiding expensive crash testing, numerical tools and methodologies are applied in evaluation of a hybrid composite test beam. Multi-scale material models capturing nonlinear strain-rate dependency, anisotropic characteristics, and failure criteria, are calibrated on a fiber reinforced plastic and a woven fabric. The fiber orientation and warp/weft angles were extracted from injection and drape molding simulation. The material laws and orientation information are coupled in a single finite element analysis to predict the performance of the hybrid composite beam under a dynamic three point bending load.
Technical Paper
2014-04-01
Haizhen Liu, Weiwen Deng, Changfu Zong, Jian Wu
Abstract This paper first presents an algorithm to detect tire blowout based on wheel speed sensor signals, which either reduces the cost for a TPMS or provides a backup in case it fails, and a tire blowout model considering different tire pressure is also built based on the UniTire model. The vehicle dynamic model uses commercial software CarSim. After detecting tire blowout, the active braking control, based on a 2DOF reference model, determines an optimal correcting yaw moment and the braking forces that slow down and stop the vehicle, based on a linear quadratic regulator. Then the braking force commands are further translated into target pressure command for each wheel cylinder to ensure the target braking forces are generated. Some simulations are conducted to verify the active control strategy. From the simulation results, it is shown that this active brake control strategy can not only ensure the flat tire vehicle stability, but also slow down the vehicle with a safe speed and for a shorter distance.
Technical Paper
2014-04-01
Erdem Uzunsoy, Emmanuel Bolarinwa, Oluremi Olatunbosun, Rui He
Abstract Sloped medians provide a run-off area for errant vehicles so that they can be safely stopped off-road with or without barriers placed in the sloped median. However, in order to optimize the design of sloped medians and the containment barriers, it is essential to accurately model the behavior of vehicles on such sloped terrain surfaces. In this study, models of a vehicle fleet comprising a small sedan and a pickup truck and sloped terrain surface are developed in CarSim™ to simulate errant vehicle behavior on sloped median. Full-scale crash tests were conducted using the vehicle fleet driven across a 9.754 meters wide median with a 6:1 slope at speeds ranging from 30 to 70 km/h. Measured data such as the lateral accelerations of the vehicle as well as chassis rotations (roll and pitch) were synchronized with the vehicle motion obtained from the video data. The measured responses were compared with responses obtained from simulation in CarSim™ to validate the vehicle and slope terrain models.
Technical Paper
2014-04-01
Tau Tyan, Jeff Vinton, Eric Beckhold, Xiangtong Zhang, Jeffrey Rupp, Nand Kochhar, Saeed Barbat
The objective of this paper focused on the modeling of an adaptive energy absorbing steering column which is the first phase of a study to develop a modeling methodology for an advanced steering wheel and column assembly. Early steering column designs often consisted of a simple long steel rod connecting the steering wheel to the steering gear box. In frontal collisions, a single-piece design steering column would often be displaced toward the driver as a result of front-end crush. Over time, engineers recognized the need to reduce the chance that a steering column would be displaced toward the driver in a frontal crash. As a result, collapsible, detachable, and other energy absorbing steering columns emerged as safer steering column designs. The safety-enhanced construction of the steering columns, whether collapsible, detachable, or other types, absorb rather than transfer frontal impact energy. Recently, more advanced steering column designs with adaptive features, mechanically or pyrotechnically activated, have been introduced for different crash conditions, including different crash severity, occupant mass/size, seat position and seatbelt usage.
Technical Paper
2014-04-01
Tau Tyan, Jeff Vinton, Eric Beckhold, Xiangtong Zhang, Jeffrey Rupp, Nand Kochhar, Saeed Barbat
This paper presents the final phase of a study to develop the modeling methodology for an advanced steering assembly with a safety-enhanced steering wheel and an adaptive energy absorbing steering column. For passenger cars built before the 1960s, the steering column was designed to control vehicle direction with a simple rigid rod. In severe frontal crashes, this type of design would often be displaced rearward toward the driver due to front-end crush of the vehicle. Consequently, collapsible, detachable, and other energy absorbing steering columns emerged to address this type of kinematics. These safety-enhanced steering columns allow frontal impact energy to be absorbed by collapsing or breaking the steering columns, thus reducing the potential for rearward column movement in severe crashes. Recently, more advanced steering column designs have been developed that can adapt to different crash conditions including crash severity, occupant mass/size, seat position, and seatbelt usage.
Technical Paper
2014-04-01
Shweta Rawat, Soumya Kanta Das
Abstract With the ever increasing emphasis on vehicle occupant safety, the safety of pedestrians is getting obscured behind the A-pillars that are expanding in order to meet the federal roof crush standards. The serious issue of pillar blind spots poses threats to the pedestrians who easily disappear from driver's field of view. To recognize this blinding danger and design the car around the driver's eye, this paper proposes the implementation of Aluminum Oxynitride marked under name AlON by Surmet Corporation for fabrication of A-pillars that can allow more than 80% visibility through them. AlON is a polycrystalline ceramic with cubic spinel crystal structure and is composed of aluminum, oxygen and nitrogen. With hardness more than 85% than sapphire, its applications range from aerospace to defense purposes which qualify it in terms of strength and thus imply that it can be conveniently used as A-pillars in vehicles. Furthermore, it possesses characteristics of being bonded to metals as well.
Technical Paper
2014-04-01
Jeong Keun Lee, Byung-Jae Ahn, Ye Ri Hong
Abstract In current inflatable curtain airbag development process, the curtain airbag performance is developed sequentially for the airbag coverage, FMVSS 226, FMVSS 214 and NCAP. Because the FMVSS 226 for the ejection mitigation and the NCAP side impact test require the opposite characteristics in terms of the dynamic stiffness of the inflatable curtain airbag, the sequential development process cannot avoid the iteration for dynamic stiffness optimization. Airbag internal pressure characteristics are can be used to evaluate the airbag performance in early stage of the development process, but they cannot predict dynamic energy absorption capability. In order to meet the opposite requirements for both FMVSS 226 and NCAP side impact test, a test and CAE simulation method for the inflatable curtain airbag was developed. The purpose of this study is to standardize the test setup for comparing the energy absorption capability of inflatable curtain airbag and to make criteria for meeting both FMVSS 226 and NCAP early in the program.
Technical Paper
2014-04-01
Qiang Yi, Stanley Chien, David Good, Yaobin Chen, Rini Sherony
Abstract According to pedestrian crash data from 2010-2011 the U.S. General Estimates System (GES) and the Fatality Analysis Report System (FARS), more than 39% of pedestrian crash cases occurred at night and poor lighting conditions. The percentage of pedestrian fatalities in night conditions is over 77%. Therefore, evaluating the performance of pedestrian pre-collision systems (PCS) at night is an essential part of the pedestrian PCS performance evaluation. The Transportation Active Safety Institute (TASI) of Indiana University-Purdue University Indianapolis (IUPUI) is conducting research for the establishment of PCS test scenarios and procedures in collaboration with Toyota's Collaborative Safety Research Center. The objective of this paper is to describe the design and implementation of a reconfigurable road lighting system to support the pedestrian PCS performance evaluation for night road lighting conditions. First, the test conditions of the road lighting (light intensity and uniformity) are generated by combining recommendations from road lighting design standards and the average measured lighting levels at various crash locations.
Technical Paper
2014-04-01
Xin Xie, Yaqian Zheng, Xiaona Li, Bernard Sia, Ping Zhong, Guobiao Yang, Lianxiang Yang
Measuring deformation under dynamic loading is still a key problem in the automobile industry. The first spatial phase-shift shearography system for relative deformation measurement is reported. Traditional temporal phase-shift technique-based shearography systems are capable of measuring relative deformation by using a reference object. However, due to its low acquisition rate, the existing temporal phase-shift shearography system can be only used under static loading situations. This paper introduces a digital shearography system which utilizes the spatial phase-shift technique to obtain an extremely high acquisition rate. The newly developed spatial phase-shift shearography system uses a Michelson-Interferometer as the shearing device. A high power laser at 532nm wavelength is used as the light source. A one mega pixels high speed CCD camera is used to record the speckle pattern interference. The spatial frequency carrier is introduced by tilting one of the mirrors in the Michelson-Interferometer.
Technical Paper
2014-04-01
Hang Yin, Weiming Zeng, Guobiao Yang, Songgang Li
Abstract When an object was subjected an impact loading, stress wave was produced in the object. Studying the regularity of stress-wave propagation was significant to the study of objects subjected to impact loading. When stress wave travelled in the object, principal stress on free boundary was useful to theoretical analysis and calculation. In this article, a new kind of dynamic photoelastic apparatus was used. Isochromatic and isoclinic of the object subjected to impact loading could be obtained combining dynamic photoelastic experiment and related test equipment. By analyzing the isoclinic, there would be a conclusion that the angle between the isoclinic and the free boundary was not 0°or 90°. So the values of the two principal stress on the boundary were all not 0. The result obtained from the electrometric method came to the same conclusion. Analysis showed the result of dynamic photoelastic method was compatible with the result of electrometric method. So the method in this article was feasible and accurate.
Technical Paper
2014-04-01
Youmei Zhao
The Hybrid III 50th male dummy is widely used in front impact crash tests in the world to evaluate the vehicle safety performance. The chest impact calibration test should be conducted after certain amount of crash tests to ensure that the dummy has the right performance during the crash tests. The impact velocity in the current chest calibration tests is 6.71 m/s and the chest displacement corridor is 63.5 mm to 72.6 mm, which was based on the cadaver tests carried out in 1970s. After over forty years' development, the vehicle safety has been improved significantly with applications of seat belt and airbag technologies. In the European and China new car assessment program (ENCAP and CNCAP), the higher performance limit for the front impact dummy chest compression is 22mm and the lower performance limit is 50 mm, which is much lower than the dummy chest calibration corridor. In this paper, the dummy rib assembly structure is analyzed and the rib impact FEA simulation was also conducted.
Technical Paper
2014-04-01
Horst Lanzerath, Niels Pasligh
Abstract Structural adhesives are widely used across the automotive industry for several reasons like scale-up of structural performance and enabling multi-material and lightweight designs. Development engineers know in general about the effects of adding adhesive to a spot-welded structure, but they want to quantify the benefit of adding adhesives on weight reduction or structural performance. A very efficient way is to do that by applying analytical tools. But, in most of the relevant non-linear load cases the classical lightweight theory can only help to get a basic understanding of the mechanics. For more complex load cases like full car crash simulations, the Finite Element Method (FEM) with explicit time integration is being applied to the vehicle development process. In order to understand the benefit of adding adhesives to a body structure upfront, new FEM simulation tools need to be established, which must be predictive and efficient. Therefore new FEM crash methods for structural adhesives have been investigated and validated with the help of test results.
Technical Paper
2014-04-01
Mathias Poklitar, Lothar Seybold
As part of the launch of the refrigerant R-1234yf there were a number of studies done regarding the ignition behavior of this new refrigerant in passenger cars. These tests were conducted by a number of automobile manufacturers, component suppliers, and the refrigerant supplier under laboratory conditions at the component and vehicle level. In November 2009 the international automotive industry concluded that the R-1234yf can be used safely in automotive air conditioning systems. Further tests were conducted by different automobile manufacturers, suppliers, and the refrigerant supplier under various laboratory and vehicle operation conditions means hot surfaces in the engine compartment. A number of vehicle manufactures have conducted full vehicle crash tests. In this paper, real world accidents are analyzed using the German In-Depth Accident Study (GIDAS) database as well as the thermal parameters for ignition of R-1234yf, i.e. concentration and surface temperature to create a worst-case scenario.
Technical Paper
2014-04-01
Bryan Styles, Jeffrey Santrock, Curtis Vincent, Michael Leffert, Narasimha Putcha
An evaluation methodology has been developed for assessing the suitability of R-1234yf in vehicles. This relates primarily to evaluating the flammability of R-1234yf in the engine compartment during a frontal collision. This paper will discuss the process followed in the methodology, the technical rationale for this process, and the results of the analysis. The specific types of analysis included in the methodology are: exhaust-system thermal characterization, computer simulated crash tests, actual crash tests, teardown and examination of crashed parts, and releases of refrigerant onto hot exhaust manifolds. Each type of analysis was logically ordered and combined to produce a comprehensive evaluation methodology. This methodology has been applied and demonstrates that R-1234yf is difficult to ignite when factors that occur in frontal crashes are simultaneously considered. Factors considered in this analysis include: crush and deformation of the vehicle structure, airflow in the engine compartment, exhaust system temperatures during different driving scenarios, and coolant release due to damage of the engine coolant system.
Technical Paper
2014-04-01
Lothar Seybold, Bryan Styles, Ioannis Lazaridis, Hans-Joerg Kneusels
The European Commission (EC) as well as the United States Environmental Protection Agency (EPA) published legislations to regulate or encourage the use of low Global Warming Potential (GWP) refrigerants applied to Mobile Air Conditioning (MAC) systems. Europe mandates a GWP less than 150 of MAC refrigerants for new vehicle types. The thermodynamic refrigerant properties of R-1234yf are slightly different from the properties of R-134a, currently used in MAC systems. Although the basic material data show that R-1234yf is flammable, ignition tests performed for an automotive engine under-hood environment reveal design and packaging influences of its ignition behavior. After extensive collaborative research in 2009, the Society of Automotive Engineers Cooperative Research Team (SAE CRP1234) concluded that R-1234yf is suitable for use in automotive applications. Further ignition risk assessment regarding R-1234yf usage in MAC systems was done by SAE CRP1234-4 in 2013. They concluded that “risks are still very small compared to the risks of a vehicle fire from all causes and well below risks that are commonly viewed as acceptable by the general public.”
Technical Paper
2014-04-01
Yohsuke Tamura, Masayuki Takeuchi, Kiyotaka Maeda, Noriaki Ohtsuka, Kenji Sato
The localized fire test provided in the Global Technical Regulation for Hydrogen Fuel Cell Vehicles gives two separate test methods: the ‘generic installation test - Method 1′ and the ‘specific vehicle installation test - Method 2′. Vehicle manufacturers are required to apply either of the two methods. Focused on Method 2, the present study was conducted to determine the characteristics and validity of Method 2. Test results under identical burner flame temperature conditions and the effects of cylinder protection covers made of different materials were compared between Method 1 and Method 2. The following results were obtained: (1) Methods 1 and 2 produced nearly identical results when the minimum temperature profile in the GTR test procedure was followed in both cases. (2) A steel protection cover on the cylinder significantly lowered cylinder surface temperatures during the fire test until activation of the thermal pressure relief device (TPRD). (3) A thermoplastic cover on the cylinder melted during the fire test and produced an engulfing pool fire during the localized fire portion of the test that accelerated activation of the TPRD.
Technical Paper
2014-04-01
Pit Schwanitz, Sebastian Werner, Johannes Zerbe, Dietmar Göhlich
Abstract A new methodology for crash sensitive vehicle structures has been developed to be used during the early stage of the Product Development Process (PDP). By frontloading significant and simplified CAE simulations and the use of stochastic optimization methods in conjunction with highly parametric CAD models, new concepts can be quickly identified and evaluated based on reliable product insight. Vehicle crashboxes have been chosen for verification of the methodology. An analysis of different but comparable vehicles showed a large variety of designs although they all absorb the energy of low speed crashes within a velocity of up to 15km/h. A powerful optimization model with a parametric geometry engine, a crash-solver and suitable optimization software, used within a batch process, has been established. The optimal results for one particular crashbox concept are presented to demonstrate the methodology and the benefit of the approach. Due to the relocation of the variant calculation at early stage, the optimization potential can be used extensively.
Technical Paper
2014-04-01
Sanjeev Kumar, Rahul Bettakote, Pinak Deb
Abstract Offset crash compliance of a compact car is severe due to the compact layout and stringent fuel economy, weight and cost targets. Scope of the current work is to improve the structural crash performance of a compact car through CAE, in order to meet the offset frontal crash requirements as per ECE R94 Regulation. The project has been classified in three main phases. First phase includes the evaluation of baseline vehicle in CAE. In order to ensure the accuracy of CAE prediction, a methodology for predicting Spotweld rupture was implemented. Using this methodology, it is possible to find out the location and time of spotweld rupture as well as propagation of spotweld rupture in CAE. CAE results of spotweld rupture prediction showed good agreement with the physical test. In second phase, design iterations were carried out in order to meet the performance targets of structural deformation. At critical locations of spotweld rupture, spotwelds were reinforced by addition of arc welds tugs and bolts.
Technical Paper
2014-04-01
Ellen L. Lee, Patrick J. Lee, Mark S. Erickson, Wilson C. Hayes
Abstract When vehicle-specific stiffness coefficients cannot be acquired, stiffness coefficient values that are representative of the desired vehicle type, class, wheelbase or weight are routinely used for accident reconstructions. Since the original compilation of representative vehicle stiffness data almost 20 years ago, changes in crash testing standards and other safety and technological improvements in vehicular design have affected vehicle stiffness. While generic frontal stiffness data have been recently updated to reflect these vehicular changes, rear and side stiffness data have not. Structural, geometric and inertial data for over 300 passenger cars and light trucks were collected. Among the vehicles targeted were the top-selling cars, SUVs, vans and pickups for model years 1990 to 2012. Results indicated that all vehicle types demonstrated increases in mean stiffness over the time period considered. SUVs were, on average, the stiffest vehicle type in the front, rear and side.
Technical Paper
2014-04-01
Dawid Trawczynski, Janusz Zalewski, Janusz Sosnowski
In the paper we discuss how a single node communication interface failure in a time-triggered system can be used to model a DoS-type attack. More so, we present a design approach based on active detection of common DoS characteristics, which can serve as a template for attack detection. This approach is feasible in time-triggered systems because of the periodic and deterministic characteristics either at the fieldbus communication or application level. We support our discussion with an example case study of a vehicle braking system implementing time-triggered messages disturbed by fault injection.
Technical Paper
2014-04-01
Satoshi Otsuka, Tasuku Ishigooka, Yukihiko Oishi, Kazuyoshi Sasazawa
Abstract In-vehicle networks are generally used for computerized control and connecting information technology devices in cars. However, increasing connectivity also increases security risks. “Spoofing attacks”, in which an adversary infiltrates the controller area network (CAN) with malicious data and makes the car behave abnormally, have been reported. Therefore, countermeasures against this type of attack are needed. Modifying legacy electronic control units (ECUs) will affect development costs and reliability because in-vehicle networks have already been developed for most vehicles. Current countermeasures, such as authentication, require modification of legacy ECUs. On the other hand, anomaly detection methods may result in misdetection due to the difficulty in setting an appropriate threshold. Evaluating a reception cycle of data can be used to simply detect spoofing attacks. However, this may result in false detection due to fluctuation in the data reception cycle in the CAN. We propose the “delayed-decision cycle detection” method for improving a conventional cycle detection method, which does not require modification of legacy ECUs, detects intrusions with a low misdetection rate, and prevents intrusions.
Technical Paper
2014-04-01
Armin Wasicek
Intellectual property rights and their protection is a cornerstone of the automotive value chain. The automotive industry is composed by a meshwork of tightly integrated organizations that cooperate and compete in a hierarchical marketplace. Trading know-how and other virtual assets between participants is an essential part of this business. Thereby, software as a medium to transport ideas, innovations, and technologies plays a particular role. Protection of virtual goods and their associated rights is a current issue whose solution will determine how business will be done in the future automotive market. Automotive experts and researchers agree that ICT security technologies are a vital part to implement such a market. In this paper we examine the software life cycle of an automotive Electronic Control Unit (ECU) and discuss potential threats and countermeasures for each stage. In particular, we will look at the following threats: (1) development (leakage of know-how through insiders or industrial espionage), (2) production (leakage through split inventor/producer companies, (3) deployment and service (manipulation of ECUs), and (4) aftersales (combating counterfeit ECUs and spare parts).
Technical Paper
2014-04-01
Qiang Chen, Yong Chen, Ola Bostrom, Yehong Ma, Eryong Liu
Abstract The aim of the study was to investigate the difference between car-to-e-bikes and car-to-pedestrian accidents. The China In-depth Accident Study (CIDAS) database was searched from 2011 to 2013 for pedestrians and e-bikes struck by car, van and SUV fronts, which resulted in 104 pedestrian and 85 e-bike cases where information was sufficient for in-depth analysis. Reconstruction by PC-Crash was performed for all of the sampled cases. Pre-crash parameters were calculated by a MATLAB code. Focus was on prototypical accident scenarios and causes; speed as well as possible prevention countermeasures. It has been shown that traffic light violations, road priority violations, and unsure safety (these situations included misjudgments, unpreparedness, proximity to other road users, inappropriate speeds, etc.…) are the main causes in both the VRU groups. Distinctions were found for aspects of car collision speed, accident scenario, distribution of head contact points and so on. Pre-impact braking/warning systems could help drivers take pre-crash measures and mitigate crash severity, but a larger field of view (FOV) for sensors is of greater necessity for e-bikers than for pedestrians.
Technical Paper
2014-04-01
Yukou Takahashi, Miwako Ikeda
Abstract The validity of evaluating FlexPLI peak injury measures has been shown by the correlation of the peak measures between a human FE model and a FlexPLI FE model. However, comparisons of tibia bending moment time histories (BMTHs) between these models show that the FlexPLI model exhibits a higher degree of oscillatory behavior than the human model. The goal of this study was to identify potential improvements to the FlexPLI such that the legform provides more biofidelic tibia BMTHs at the normal standing height. Impact simulations using a human FE model and a FlexPLI FE model were conducted against simplified vehicle models to compare tibia BMTHs. The same series of impact simulations were conducted using the FlexPLI models that incorporated potential measures to identify measures effective for further enhancement of the biofidelity. An additional analysis was also conducted to investigate the key factor for minimizing the oscillation of the tibia BMTH. The results of this study showed that the change of the mass distribution between the bony and flesh parts, along with the addition of the mass compensating for the upper body, provide more biofidelic FlexPLI tibia BMTHs, when used at the normal standing height.
Technical Paper
2014-04-01
Chinmoy Pal, Tomosaburo Okabe, Kulothungan Vimalathithan, Jeyabharath Manoharan, Muthukumar Muthanandam, Satheesh Narayanan
Abstract A logistic regression analysis of accident cases in the NASS-PCDS (National Automotive Sampling System-Pedestrian Crash Data Study) database clearly shows that pedestrian pelvis injuries tend to be complex and depend on various factors such as the impact speed, the ratio of the pedestrian height to that of the bonnet leading edge (BLE) of the striking vehicle, and the gender and age of the pedestrian. Adult female models (50th %ile female AF50: 161 cm and 61 kg; 5th %ile female AF05: 154 cm and 50 kg) were developed by morphing the JAMA 50th %ile male AM50 and substituting the pelvis of the GHBMC AM50 model. The fine-meshed pelvis model thus obtained is capable of predicting pelvis fractures. Simulations conducted with these models indicate that the characteristics of pelvis injury patterns in male and female pedestrians are influenced by the hip/BLE height ratio and to some extent by the pelvis bone shape. A previously developed six-year-old (6YO) child pedestrian model and the newly developed models were used to estimate the head impact time (HIT) for a typical SUV fitted with an active pop-up hood system.
Technical Paper
2014-04-01
Stacy M. Imler, Michelle F. Heller, Christine C. Raasch, Heather N. Watson, Ke Zhao
Abstract The risk of sustaining injury in rear impact collisions is correlated to collision severity as well as other factors such as restraint usage. The most recent National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) data available (1997 to 2011) were analyzed to identify accidents involving passenger vehicles that have experienced an impact with a principal direction of force (PDOF) between 5:00 and 7:00, indicating a rear impact collision. The Abbreviated Injury Scale (AIS) was used as an injury rating system for the involved vehicle occupants who were at least sixteen years old and were seated in the outboard seating positions of the front row. These data were further analyzed to determine injury risk based on resultant delta-V and restraint system use. Each body region (head, spine, thorax, abdomen, upper extremity, and lower extremity) was considered separately. Risk of injury for each of these regions was examined based on delta-V, which is an indicator of crash severity in the absence of intrusion into the occupant compartment.
Technical Paper
2014-04-01
William N. Newberry, Stacy Imler, Michael Carhart, Alan Dibb, Karen Balavich, Jeffrey Croteau, Eddie Cooper
Abstract It is well known from field accident studies and crash testing that seatbelts provide considerable benefit to occupants in rollover crashes; however, a small fraction of belted occupants still sustain serious and severe neck injuries. The mechanism of these neck injuries is generated by torso augmentation (diving), where the head becomes constrained while the torso continues to move toward the constrained head causing injurious compressive neck loading. This type of neck loading can occur in belted occupants when the head is in contact with, or in close proximity to, the roof interior when the inverted vehicle impacts the ground. Consequently, understanding the nature and extent of head excursion has long been an objective of researchers studying the behavior of occupants in rollovers. In evaluating rollover occupant protection system performance, various studies have recognized and demonstrated the upward and outward excursion of belted occupants that occurs during the airborne phase of a rollover, as well as excursion from vehicle-to-ground impacts.
Technical Paper
2014-04-01
Mark William Arndt, John Wiechel
Abstract Assuming rigid body motion, recorded acceleration and recorded roll rates at the center of gravity, equations are used to calculate the local three-dimensional accelerations at hypothetical seating positions' Emergency Locking [seat belt] Retractors (ELR) during a steer induced rollover crash. For a threshold of 0.7 g, results demonstrated that intervals in the vehicle's response that may cause the ELR's inertial sensor to move into a neutral zone were limited to localized high magnitude negative vertical acceleration events during the rollover segment with a median duration of 4 ms, average duration of 4.8 ms and a maximum calculated duration of 31.7 ms. Changing the threshold to 0.35 g reduced the interval count by 70 percent and maximum duration by approximately 50 percent. Since a retractor in an interval when an inertial sensor may move into a neutral position will unlock only after belt retraction and at an acceleration ratio below its threshold, the duration that a retractor may be unlocked was probably less than the duration of an interval when a vehicle's response would allow an inertial sensor to move into a neutral zone.
Viewing 241 to 270 of 15812

Filter

  • Article
    485
  • Book
    104
  • Collection
    42
  • Magazine
    615
  • Technical Paper
    10011
  • Standard
    4555
  • Article
    4555